ABSTRACT Obesity is a major health problem in the United States and associated with increased risk of diabetes. There is a great need for interventions that can assist with long-term maintenance of healthy body weight and be sustainably integrated into existing health care teams. We have developed and tested an innovative weight loss maintenance intervention ? Maintaining Activity and Nutrition through Technology-Assisted Innovation in Primary Care (MAINTAIN-pc) ? delivered through the electronic health record (EHR) to help patients maintain recent intentional weight loss and successful lifestyle strategies. We have conducted and published results from a randomized clinical trial of MAINTAIN-pc at the University of Pittsburgh and found that participants who received EHR tracking tools and personalized coaching had significantly lower weight regain at 24 months (primary outcome) than participants who received EHR tracking tools alone. MAINTAIN-pc leveraged commonly available health information technology (HIT) tools to track participant progress and support patients and their providers in ongoing efforts to maintain weight loss. Despite the success of MAINTAIN-pc, two key questions about the practicality and sustainability of this intervention remain unanswered: (i) whether the HIT could be adapted at other sites and (ii) whether coaching could be delivered leveraging existing staff resources rather than interventionists supported by a research grant. We propose a pragmatic clinical trial to test the implementation and impact of the MAINTAIN-pc protocol in routine healthcare settings: MAINTAIN PRIME (Promoting Real (World) IMplEmentation). MAINTAIN PRIME will be conducted in 14 primary care practices affiliated with the University of Utah and will capitalize on further advances in HIT (e.g., dashboards to track patient populations) and team-based care models to deliver the intervention with minimal support from research staff. MAINTAIN PRIME will measure costs to inform future sustainability, and it will study workflow and individual, clinical, and organizational attributes to determine facilitators and barriers to successful implementation. Our proposed project will include three phases: 1) pre-implementation, in which we will do collaborative implementation design with clinic and IT teams and vanguard implementation mapping; 2) implementation, in which we will conduct a pragmatic clinical trial with weight change at 24 months as the primary outcome; and 3) post-implementation, in which we will evaluate the success of MAINTAIN PRIME, including barriers, facilitators, and costs that will inform future sustainability and be summarized in a ?toolkit? to foster dissemination. By focusing on weight maintenance and relapse prevention, increased use of existing staff, and integration with HIT systems and tools, we will fill a crucial gap in the long-term treatment of obesity as a chronic medical condition.